Book Image

Learn Power Query

By : Linda Foulkes, Warren Sparrow
Book Image

Learn Power Query

By: Linda Foulkes, Warren Sparrow

Overview of this book

<p>Power Query is a data connection technology that allows you to connect, combine, and refine data from multiple sources to meet your business analysis requirements. With this Power Query book, you’ll be empowered to work with a variety of data sources to create interactive reports and dashboards using Excel and Power BI. </p><p>You’ll start by learning how to access Power Query across different versions of Excel and install the Power BI engine. After you've explored Power Pivot, you’ll see why Excel users find it challenging to clean data in Power Pivot and learn how Power Query can help to tackle the problem. The book will show you how to transform data using the Query Editor and write functions in Power Query. A dedicated section will focus on functions such as IF, Index, and Modulo, and creating parameters to alter query paths in a table. You’ll also work with dashboards, get to grips with multi-dimensional reporting, and create automated reports. As you advance, you'll cover the M formula language in Power Query, delve into the basic M syntax, and write the M query language with the help of examples such as loading all library functions offline in Excel and Power BI. Finally, the book will demonstrate the difference between M and DAX and show how results are produced in M. </p><p>By the end of this book, you’ll be ready to create impressive dashboards and multi-dimensional reports in Power Query and turn data into valuable insights.</p>
Table of Contents (17 chapters)
Free Chapter
1
Section 1: Overview of Power Pivot and Power Query
6
Section 2: Power Query Data Transformations
11
Section 3: Learning M

Creating a function manually using M

Just like Excel, Power Query (and Power BI) has many functions that you can use to prepare or transform data. These are, of course, updated regularly by developers. When we use icons and set options in Power Query, the program works hard behind the scenes to generate the code to provide you with results to any functions you may apply to the data.

We can display a list of M functions using the #shared code in the Power Query formula bar, as explained in Chapter 9, Working with M, in the Using #shared to return library functions section. We can use this to build our data queries, but sometimes, we need to construct personalized functions to make our lives easier and less complicated. By less complicated, we mean being able to address repetitive tasks with one action instead of multiple actions or construct them so that they can be applied to many different queries or arguments. We will use a manual method of creating a custom function by constructing...